Open aaronsnoswell opened 6 years ago
hi @aaronsnoswell we ar currently not supporting URDF anymore, since they are not suitabe for simulation, we are refactoring the whole project and going to use SDF for the robots description. There is also a urdf to sdf parser maintained from gazebo that can be used to load robots.
It will still be a while though until the project will be usable since we are a bit limited with time to invest on this, plus unreal lack of joints (they abstracted away from the physics engine and use constraints for this) is giving us a bit of conversion issues :)
Thanks for letting me know @andreihaidu.
Can you let me know the current status of your SDF importing project? I ask because I'm having issues importing a valid .urdf with this plugin (see #24), and would like to get my robot into UE4. If SDF is the way forward, then maybe I can get started on updating this plugin to SDF support? I wouldn't want to waste time on something you've already started though.
Thank you again,
Steps to reproduce: Copy the example PR2 URDF and associated meshes to a new project's XML folder. Modify the pr2.urdf to comment out the contents of the "base_link" link, (e.g. see below code). Import this URDF into Unreal (this should work fine). Now try dragging the imported URDF into the scene.
Observed behaviour: The editor crashes. The error is a null pointer exception on line 393 of RRobot.cpp - upon reaching the "base_bellow_link" (3 calls deep into the
ARRobot::CreateActorsFromNode()
function), the code tries to access*ParentComp->GetName()
, but ParentComp is Null. See the below image.Expected behaviour: My understanding is that a URDF can be valid, even if the base link has no collision or visual geometry - e.g. see the spec at this link or the fact that I can run
check_urdf pr2.urdf
on the modified URDF file and it parses correctly. As such, this URDF should import no worries.My actual use case is another robot URDF we have, but I was able to reproduce this error with the PR2 URDF, which I figured would be easier for you to reproduce at your end.
I'm happy to try and put together a PR to fix this, but it seems to be a logic error in the parsing of
<link />
nodes in URDF files. As such, I'm not sure how to fix this. Any guidance you could offer would be great.Thank you for this great plugin.